Earthquake early warning systems can provide a few to a few tens of seconds warning prior to damaging ground shaking, depending on the distance of the warned entity from the epicenter. Essentially, early warning systems use accelerometers to detect the initial primary wave (P-wave) of a quake, which typically is perceived as a jolt and which precedes the more damaging secondary waves (S-waves) because the P-wave travels faster.
Although providing only a short window of warning, an early warning system nonetheless can allow for short-term mitigation including slowing and stopping of transportation systems, switching industrial and utility systems to a safe mode, and taking personal protective measures. In other words, while a few seconds may not sound like much, it is enough time for school children to dive under their desks, gas and electric companies to shut down or isolate their systems, phone companies to reroute traffic, airports to halt takeoffs and landings, and emergency providers to pinpoint probable trouble areas. Such actions can save lives and money. As understood herein, it is possible to leverage existing infrastructure to provide such early warning of an impending earthquake.